Sexually Dimorphic Effects of a Single Neonatal Δ9-tetrahydrocannabinol Exposure on Neuronal Dendritic Morphology and Cognitive Functions in Rats.
Cannabis and Cannabinoid Research February 1, 2026 Meetu Wadhwa, Gregory A Chinn, Katrina Duong et al.
A single injection of THC (5 mg/kg) given to rat pups on the third day after birth caused lasting spatial memory deficits in young adult females but not males. Anxiety-like behavior was unchanged in either sex. Both sexes showed decreased spine density, dendritic length, branching, and complexity in neurons of the frontal cortex and hippocampus (CA1, CA3, dentate gyrus). The results indicate that even brief neonatal cannabinoid exposure can produce long-lasting, sex-dependent cognitive impairment and structural brain changes, highlighting the vulnerability of the developing brain.